In general, a fabricating process by a semiconductor fabrication apparatus mainly employs a washing method in which a semiconductor wafer or a substrate, such as glass for LCD (hereinafter, referred to as a ‘wafer’), is successively immersed in a washing tank containing a washing solution, such as a chemical solution or a rinse solution. In addition, a drying method is known that includes the application of vapor, produced from a volatile organic solvent (e.g. isopropyl alcohol (IPA)), to a washed wafer surface, where the vapor is condensed or adsorbed, and the provision of an inert gas, such as N2 gas (nitrogen gas), to the wafer surface to remove and dry the moisture on the surface (for example, refer to Japanese Laid-Open Patent No. 2007-5479).
In the drying method described above, when the vapor of the organic solvent is supplied to a chamber housing a wafer, an evaporator is used that generates the organic solvent vapor by evaporating the liquid of the organic solvent by applying heat. For example, Japanese Laid-Open Patent No. 2007-17098 discloses the aforementioned evaporator.
A conventional evaporator disclosed in Japanese Laid-Open Patent No. 2007-17098 includes a heat source lamp, such as a halogen lamp, and a helical fluid tube surrounding the heat source lamp, in which the fluid of an organic solvent to be heated flows. The liquid of the organic solvent flows in the helical fluid tube, and is heated through the heating of the fluid tube by the heat source lamp, thereby generating the vapor of the organic solvent within the fluid tube.
In a conventional evaporator disclosed in Japanese Laid-Open Patent No. 2007-17098, organic solvent liquid is mixed with an inert gas, such as N2 gas, and the mixed fluid of the organic solvent liquid and the inert gas is then sent to a fluid tube. Herein, the inert gas functions as a carrier gas. However, in such an evaporator, since the organic solvent liquid sent to the fluid tube includes an inert gas, a problem exists in that the organic solvent is diluted by the inert gas, and the concentration of the organic solvent vapor generated within the fluid tube become lower.